Charge carrier transition in an ambipolar single-molecule junction: Its mechanical-modulation and reversibility

Abstract

Single-molecule switch for modular electronics Applying force to a junction linking gold atoms leads to reversible switching of its electric properties, facilitating development of single-molecule devices. Building electronics from the molecular level up could lead to drastically smaller electronic circuits. Precisely controlling their functionality at the single-molecule scale is challenging. Yue Zheng and colleagues from China’s Sun Yat-sen University demonstrated by computer simulation that a cyclopropane-1,2-dithiol ring linking two gold atoms can be opened and closed reversibly and repeatedly using mechanical force, switching its electric properties from one that internally donates electrons to one that accepts them. Using the molecule as modular building block, they design a multifunctional junction that, with the application of mechanical force, exhibited resistance (increasing voltage leads to increased current), rectification (converts alternating current to direct) and negative differential resistance (increasing voltage leads to decreased current).